Method for optimally managing the charging of a fleet of electric vehicles

Abstract

A method is performed for optimizing the management of the charge of a set of electric batteries, where each battery is recharged during a time interval during which it is connected to an electricity distribution network, according to a charge profile provided by a charge aggregator, by applying, under the control of a charge manager of the battery, a charging power level. The method involves determining, on the aggregator side, as a charge profile, a distribution curve of the charge per day over a given period of time, defined for all the batteries solely according to constraints specific to the network, transmitting the charge distribution curve to each charge manager and, on the charge manager side, adapting the received charge distribution curve to the time interval during which the battery is connected to the network and to the associated charging power level.

The invention claimed is: 
     
       1. A charging method for optimally managing charging of at least one set of electric batteries for supplying power to electrical consumers, in which each of the batteries is recharged for at least one time interval during which it is connected to an electricity distribution grid, according to a charging profile supplied by a charging aggregator, by applying, under a control of a charging manager associated with each of the batteries, a charging power level associated with the time interval, the charging method comprising:
 on the aggregator side, determining the charging profile to be a curve of distribution of charging per day over a given time period, defined for all the batteries solely depending on constraints specific to the electricity distribution grid comprising at least the power available on the electricity distribution grid; 
 transmitting the charge distribution curve from the aggregator to each charging manager, and the charge distribution curve received on the charging manager side includes the at least one time interval during which the battery is connected to the grid and to the associated charging power level; 
 determining for all of the batteries a coefficient representative of a percentage to be reached per day with respect to a flexibility range permitted by the charging manager, the range is defined depending on a nominal capacity of the battery and on a minimum state of charge desired per day, and computing a daily target state of charge to be reached depending on the coefficient and on the minimum state of charge desired per day; and 
 controlling charging and discharging moments of each of the batteries through the electricity distribution grid by monitoring the charge distribution curve. 
 
     
     
       2. The charging method as claimed in  claim 1 , wherein
 the determining of the charging profile depends on CO2 emissions associated with the generation of electricity on the electricity distribution grid over the given period. 
 
     
     
       3. The charging method as claimed in  claim 2 , further comprising
 receiving a prediction model for CO2 emissions from which model an average of the CO2 emissions over the given period and an average of the CO2 emissions per day are deduced and the level of the CO2 emissions at a time is compared to the average of the CO2 emissions per day, so that the charging profile is adapted to command charging only at moments when the level of CO2 emissions is below the average per day. 
 
     
     
       4. The charging method as claimed in  claim 1 , wherein
 the charge distribution curve is calculated in a percentage of charge with respect to time for a given sampling increment. 
 
     
     
       5. The charging method as claimed in  claim 1 , wherein
 the given time period corresponds to a time period of one week. 
 
     
     
       6. The charging method as claimed in  claim 1 , wherein
 the charging power level during each time interval is determined based on a comparison between the daily target state of charge to be reached and a current state of charge of the battery. 
 
     
     
       7. The charging method as claimed in  claim 1 , wherein
 the percentage to be achieved per day with respect to the flexibility range authorized by the charge manager varies inversely with the level of the CO2 emissions associated with the generation of electricity on the electricity distribution grid over the given period. 
 
     
     
       8. The charging method as claimed in  claim 1 , wherein
 the set of batteries consists of traction batteries of a fleet of electric or rechargeable-hybrid vehicles.